Alabaster

• 2 1/2 pounds baking potatoes, peeled and cut into roughly 1-inch cubes
• 1 pound turnips, peeled and cut into roughly 1-inch cubes
• 3/4 to 1 cups light cream, half-and-half, or heavy cream, at room temperature
• 1/3 to 1/2 cups buttermilk, at room temperature
• 2 to 3 tablespoons unsalted butter, at room temperature
• Salt and ground white pepper, to taste

1. Bring a large pot of salted water to a boil. Add the potatoes and turnips. Boil uncovered, not too vigorously, until both are tender, about 15 minutes.
2. Drain the potatoes and turnips in a colander, shaking to remove most of the water. Return them to the pot and shake over low heat for about 30 seconds to dry them. Remove from the heat.
3. Add the smaller amounts of cream, buttermilk, and butter. Use a potato masher to break up the potatoes and turnips just as much as you like. (Traditionally, the dish is creamy smooth.) Add more cream, buttermilk, and/or butter to suit your taste for flavor and consistency. Add salt and white pepper to taste.
4. Transfer to a warm bowl and serve.

baking potatoes, cubes, light cream, buttermilk, unsalted butter, salt

Taken from food52.com/recipes/7871-alabaster (may not work)